A computer network is a collection of computers and other hardware interconnected by communication channels that allow sharing of resources and information. Communication protocols define the rules and data formats for exchanging information in a computer network. A gateway on a network is a node on the network equipped for interfacing with another network or networks. The gateway is often used for passing data between devices on different networks. Transport Layer Security (TLS) and Secure Socket Layer (SSL) are two examples of cryptographic communication protocols that provide communication security by allowing devices to exchange encrypted, as opposed to plaintext, messages.